3-acyloxy-7,11-diketo-8-dehydrotigogen



United States Patent- O 3-ACYLOXY-7,11-DlKETO-8-DEHYDROTIGOGEN Earl M. Chamberlin, Westfield, and John M. Chemerda,

Metuchen, N. J., assignors to Merck & Co., Inc., Rahway, N. 1., a corporation of New Jersey No Drawing. Original application September 20, 1951, Serial No. 247,562, and March 10, 1951, Serial No. 215,626. Divided and this application November 26, 1957, Serial No. 703,722

2 Claims. (Cl. 260-23955) This application is a division of copending applications Serial No. 215,026, filed March 10, 1951, now abandoned, and Serial No. 247,562, filed September 20, 1951.

This invention is concerned with novel chemical compounds of the cyclopentanopolyhydrophenanthrene series and processes for preparing the same; more particularly, it relates to novel cyclopentanopolyhydrophenanthrene compounds having functional substituents in ring C; and specifically it relates to new compounds having' a hydroXyl or keto substituent at the 11 position, and to processes for the preparation of such compounds.

Compounds of the adrenal cortex, such as Kendalls compound E (cortisone) have been found to be of great value in the treatment of various diseases. Further, it is likely that Kendalls compound E and/ or other closely related ll-hydroxy steroids will find increasing therapeutic use in the future. Unfortunately, the only method for the preparation of such compounds presently available utilizes desoxycholic or cholic acids as the starting material. Cholic and desoxycholic acids have hydroxy substituents in ring C at the 12 position, thus providing a means for introducing a functional substituent at the 11 position. However cholic and desoxycholic acids, which are obtained from animal bile, are only available in limited amounts. Heretofore no practical method was available whereby a functional group could be introduced in ring C which would permit the use of more abundant steroids such as the sterols, ergosterol, cholesterol, stigmasterol, or plant sapogenins, such as diosgenin, tigogenin, and the like.

It is an object of the present invention to provide a process for introducing a functional group in ring C at the 11 position. It is a further object to provide a process for converting cyclopentanopolyhydrophenanthrene compounds having a double bond in the 7:8 position to the corresponding cyclopentanopolyhydrophenanthrene compound having a hydroxyl or keto group at positions 7 and 11. Another object is to provide new compounds of the steroid series having functional groups in ring C suitable for the preparation of other cyclopentanopolyhydrophenanthrene compounds. Other, objects will be apparent from the detailed description hereinafter provided.

' In accordance with our invention, we have now found that compounds of the cyclopentanopolyhydrophenanthrene series having an ll-keto substituent can be synthesized by reactions indicated as follows:

VII

These reactions are carried out as follows:

A cyclopentanopolyhydrophenanthrene compound having a 7:8 double bond (I) is reacted with mercuric acetate producing the corresponding compound having conjugated double bonds in the 7:8 and 9:11 posi- The A -7,1 1-dihydroxy compound IV is reacted with an oxidizing agent to convert the hydroxy substituents to .keto groups, thus. obtaining the corresponding A -7,11-

diketo cyclopentanopolyhydrophenanthrene derivatives (V). These diketo compounds are then reduced to saturate the A double bond and form the corresponding 7,11-diketo compound VI. The saturated diketo compound is then reduced to eliminate the 7-keto substituent, thus producing the corresponding ll-keto compound VII. The latter compounds are useful intermediates for the preparation of ll-keto compounds having desirable therapeutic properties.

The A' -compounds of the cyclopentanopolyhydrophenanthrene series are conveniently prepared by reacting the corresponding A' -compound with mercuric acetate. We have found that this reaction is preferably effected by reacting the A' -compound with mercuric acetate and glacial acetic acidin the presence of a suitable solvent medium;such as chloroform. The reaction is conveniently conducted by stirring the reaction mix ture for 16-24 hours. After the reaction is completed, the A -compound is recovered from the reaction mixture by removing the precipitated mercurous acetate, and concentrating the solution under'diminished pressure. If desired, the residue may be further purified by crystallization from suitable solvents. Thus, this process can be utilized to prepare A -pregnadiene-3-ol-20- one-3-acetate, and A -dehydrotigogenin acetate from A' -pregnenolone acetate and A' -dehydrotigogenin acetate respectively. Alternatively, other acyl derivatives of these starting materials or the 3-hydroxy compounds may be utilized as starting materials inour process. to prepare the corresponding A -compounds.

Further, the 3-hydroxy-A -choladienic acid, which is also useful as a starting material in the processes of our invention, is readily obtained by reducing 3-hydroxy- 12-keto-A -choladieuic acid. This is conveniently accomplished by reacting the keto acid with hydrazine hydrate and an alkali metal hydroxide in the presence of a suitable high boiling solvent such as diethylene glycol.

This invention is concerned with compounds of the type represented by intermediates V and VI above, and with processes of producing the same. Compounds V and VI may be represented by the following formulas:

V VI

The starting materials used in the process of this invention, namely-the A -dihydroxy compounds shown by Formula IV, may be obtained as described in copending application Serial No. 215,026, now abandoned, filed March 10, 1951.

Pursuant to our invention, we have found that the A'-7,11-dihydroxy compounds are readily oxidized to obtain a new series of compounds having a double bond in the 8:9 position and keto substituents in the 7 and 11 positions. This oxidation is readily accomplished for example by treating the A -7,11-dihydroxy compounds with chromic acid in the presence of an acid such as acetic or sulfuric acid. We have found that an oxidation mixture consisting of chromic acid-acetone-sulfuric acid is particularly useful for this oxidation, and results in the obtainment of maximum yields of the desired diketo compound under optimum conditions. In carrying out this process, it is necessary to protect any other hydroxyl substituents, for example, a 3-hydroxy group, by convertingjthisgroup to an acyloxy substituent. After theoxidation, any. such acYlQXy substituents can be readily hydrolyzed to prepare the corresponding .hydroxy compounds.

These new A -7,11 diketocyclopentanopolyhydrophenanthrene compounds are reduced to saturate the 8:9 double bonds and produce the corresponding saturated 7,1l-diketo compound. This reduction is conveniently accomplished for example by reacting the A compound with zinc in the presence of acetic acid.

In accordance with the above-described methods, cyclopentanopolyhydrophenanthrene compounds having 7,11 diketo substituents such as, 3-acyloxy-7,1l-diketo-A ergostadiene, 3-acyloxy-7,11-diketo-A -bisnorallocholenic acid and its esters, 3-acyloxy-7,1l-diketo-A -cholenic acid and its esters, 3-acyloxy-7,ll-diketo-d -tigogenin, A'- allopregnene-3-ol-7,11-20-trione and its acyl derivatives, and the like can be obtained by the oxidation of the corresponding 7,11-dihydroxy-compounds. Further, these diketo compounds may be reduced to the corresponding compounds having a saturated bond in the 8:9 position.

The following examples are presented to illustrate specific embodiments of our invention.

EXAMPLE 1 Preparation of 3-acetoy-7,11-diket0-A" -erg0stadiene from 3-acen0xy-7J1-dhydr0xy-A" -ergostadiene Two hundred milligrams of 3-acetoxy-7,1l-dihydroxy- Analysis-Cale. for c,,,H,,o.,= c, 76.88; H, 9.46. Found: 0, 76.91; H, 9.58.

max. 2660 A. (E% 200--iso-octane) max. 2700 A. (E% 186,-ethanol) QD 3i C1s).-

EXAMPLE 2 Preparation of 3-acetoxy-7,I 1 -diketa-A -erg0stadiene I from 3-acet0xy-7,11-dihydroxy-A -ergostadiene To a stirred suspension of 2.36 g. of 3-acetoxy-7,11-dihydroxy-A -ergostadiene in 50 ml. of purified acetone was added asolution of 6.65.millimols of chromic oxide in 5 ml. of 3.6 N sulfuric acid. The mixture was stirred at 10 C. for 10 minutes,,after which 2 ml. water was added, and the mixture was stirred for 25 minutes at room temperature. The green inorganic material-which had separated was removed by filtration. The filtrate was stirred while.50 ml. water were added. The product was collected on afilter and washed with water. After drying in vacuo over phosphorous pentoxide the product, 3-acetoxy-7,l1-diket0-A -ergostadiene, was obtained in the form of a light yellow powder. Yield: 2.26 g., M, P. 103-114" C., A max. 2660 (E% l2lethan'0l).

EXAMPLE 3 Preparation of 3-acet0xy-7,1l-diketo-A -ergostene from 3-acetoxy-7,11-diket0-A" -ergostadiene A hot solution of mg. of 3-acetoxy-7,l1-diketo- A -ergostadiene in 5 cc. of acetic acid and 0.1 cc. of water was treated with 250 mg. of zinc. The initially yellow solution was decolorized rapidly and the mixture heated on the steam bath for three hours. Water was then added to recipitate the diketone, which was dissolved in benzene. Upon removal of the benzene, a residue was obtained which was recrystallized from methanol. Yield: 70 mg.; M. P. 196-198 C.; a 25 (1.0% CHCl Analysis.-Calc. for C H O Found: C, 76.68; H, 9.59.

Alkaline hydrolysis of 3-acetoxy-7,11-diketo-A ergostene yielded 3-hydroxy-7,11diketo-A -ergostene, M. P. 198 l99 C.

Analysis.Calc. for C H ;O Found: C, 78.28; H, 10.09.

EXAMPLE 4 Preparation of methyl 3-acetoxy-7,1l-dilceto-A -bisnorallocholenate from methyl 3-acet0xy-7J1-dihydroxy- A -bl'snorallocholena-te To a stirred solution of 1.60 g. of methyl 3-acetoxy- 7,11-dihydroxy-A -bisnorallocholenate in 30 ml. of glacial acetic acid, was added a solution of 0.730 g. of sodium dichromate dihydrate in 30 ml. of glacial acetic acid over a period of minutes. After stirring at C. for two hours, the mixture was concentrated in vacuo to a small volume. The residue was shaken with 50 ml. of benzene and 50 ml. of water. -The aqueous layer was extracted twice with 25 ml. portions of benzene. The combined benzeneextracts were washed with-50 ml. of water, dried over anhydrous sodium sulfate, and the benzene was removed by vacuumdistillation. The residual oil was triturated with 3 ml. of cold methanol and the resulting crystalline product was collected and washed with cold methanol. Yield 550 mg., M. P. 183 185.5 C. After two recrystallizations from methanol, the melting point of the diketo compound was raised to 186.5-187.5 C. [a] =+38.7 (C.=1.04, CHC13) max. 2700; E% 212.

Analysis.-Calc. for C H O C, 69.74; H, 7.96.

Found: C, 70.00; H, 8.12.

EXAMPLE 5 Methyl 3-hydroxy-1 1 keto-bisnordllocholamte AcO-- COOCHs AcO- dryness. The residuein the flask was dissolved by shaking twice with a mixture of 25 cc. of 5% sulfuric acid and 50 cc. of benzene. The combined benzene solutions were dried over anhydrous magnesium sulfate, and the benzene was evaporated on the steam bath in a stream of nitrogen.

The residue was dissolved in 200 cc. of ether and stirred with 5 g. of sodium carbonate and 2 cc. of water for 21 hours. The sodium salt of 3-acetoxy-7,11- diketo-bisnorallocholanic acid (II) was filtered off and dried in a vacuum desiccator.

The dried sodium salt was suspended in 25 cc. of ether and 25 cc. of 50% sulfuric acid was added in small portions until the mixture was definitely acid. cc. of ether was added to bring about complete solution of all solids. The aqueous layer was separated and extracted once with 50 cc. of ether.

The combined ethereal solutions were dried over anhydrous magnesium sulfate. and then evaporated on the steam bath to a small volume, whereupon 3-acetoxy-7,lldiketo-bisnorallocholanic acid (H) crystallized out. The product was recrystallized from ether; M. P. 235-238 C., [a] =24-.6; a=0.68 C.=1.38%' CHCl Analysis..Calcd.-f0r C H O C, 68.87; H, 8.19. Found: C, 68.67; H, 8.04.

mg. of 3-acetoxy-7,1l-diketo-bisnorallocholanic acid was suspended in 25 cc. 'of ether and esterified with diazomethane. All solid dissolved and on evaporation of the ether to a small volume, the methyl ester (III) crystallized. M. P. 226.5229 C. Mixed melting point with an authentic sample of the ester: 227-230 C.

5 *g. of methyl 3-acetoxy-7,ll-diketo bisnorallocholanate (III) and 2.07 g. of powdered potassium hydroxide were placed in a 50 cc. round-bottom flask. '25 cc. of diethylene glycol and 2.3 cc. of 85% hydrazine hydrate were added and the temperature raised to 140 C. and held for 1 hour. The temperature was then raised to l95-200 C. and held for 2 hours. a

After cooling, the reaction'rnixture was dissolved in benzene and water, 50% sulfuric acid added until an acid reactionwas obtained. The benzene layer was separated, and the aqueous layer extracted three times with 50 cc. of benzene. The combined benzene solutions were washed with water and dried over anhydrous magnesium sulfate.

The benzene was treated with Darco; The benzene solution was concentrated in vacuo to dryness, the residue was dissolved in ether and esterified with an ethereal solution of diazomethane. The ether was evaporated, and the methyl 3-hydroxy-1 l-keto bisnorallocholanate (IV) was recrystallized from methanol, M. P. 1775-- 180.5. Mixed M. P. with an authentic sample, 177179 C., [u] =-|-41.

EXAMPLE 6 Preparation of methyl 3-acetoxy-7,1J-diketo-bisnorallocholanate from methyl 3-acetoxy-7,1l-diketo-A -bisnorallocholenate A mixture of 400 g. ofmethyl 3-acetoxy-7,l1-diketo- M-bisnorallocholenate, 20 ml. of glacial acetic acid, 0.4 ml. water, and 1.5 g. zinc dust was heated for one hour on the steam bath. One gram of zinc dust was added, and the mixture was heated for two houns more. After cooling to room temperature, 50 ml. water were added to the mixture. The precipitated product, along with residual zinc, was collected on a filter. The dried mixture was extracted with benzene. After removal of the henzene by vacuum distillation, the product, methyl 3-acetoxy-7,11-diketo-bisnorallocholanate was recrystallized from methanol. Yield: 270 mg., M. P. 230-231.5 C. The analytical sample was recrystallized from methanol, M. P. 230.5231.5 C., [111 14.5 (C.=1.55, CHClg).

Analysis.-Calc. for C H O C, 69.41; H, 8.39, Found: C, 69.70; H, 8.40.

73.7 EXAMPLE .7

Preparation of methyl 3-acet0xy-7,II-diketo-M-choIenate from methyl 3-acetoxy'-7,1l-dihydroxy-A -cholenate ,To..a stirred suspension of 1.7 g. of;methyl 3-acetoxy- 7,1l-dihydroxy-A -cholenate in 100 cc. acetone was .added at.20. .C. with stirring a.s'olution of 0.5 g. chromium trioxideinj 4 .cc. of 10% zsulfuricnacid over aperiod Iof;ten minutes. ,After-addition was .complete, the mixture was stirred for'onetand one half hours. The inorganic residue was filtered off and washed with'three 10 cc. portions, of acetone. ITheacetone solution was added with stirringto 66 cc. water and the 7,l1-.diketo.compound whichprecipitated.svasfiltered, washed free of. acid with water'anddried. .Yield: 1.57 g.; M. P. 112.5-113.5 C.

.After. recrystallization from. ethanol the product, methyl 3-acetoxy-7,1l-dilcetoaa gcholenate melted at 114115 C..

.Analysis...Calc. fOI' C HaoOgI Found; C, 70.93.; H,.8.3.0.

EXAMPLE 8 Preparation of methyl 3-acet0xy-7,11 diket-cholanate from methyl 3-acet0xy-7,1'1-diketo-A-ch0lenate A mixture of 1.57 g. ofmethyl 3-acetoxy-7,l1-diketo- A -cholenate, 17 cc. acetic acid, 1.7 cc. water and, 3.4 g. zinc dust was heated on a. st,earn bath for onehour.

The reaction mixture, wasdiluted with 80 cc. benzene and the zinc residue was filtered ofl. The benzene solution was washed free of acid with water, dried over anhydrous sodium sulfate and concentrated to dryness.

Yield: 1.57 g. V g

The product was purified by recrystallization from ethanol. Yield: 1.17 g.; M. P. 1623 C..

Analysis.-Calc. for. C I-1 0 C, 70.10; H,, 9.15.

TEXAMPLE' 9 Preparation of 3-acet0xy-Z1 1rdiket08 dehydrotigogenin from 3-acetoxy-7,11vdihydroxy-8-dehy 1r0tigogenin To a suspension 0f'0.3'46 'g; (0.71 millimol) of 3-acetoxy-7,l1-dihydroxy-8-dehydrotigogenin in 10 ml. of ace 8 226227 .C.. [nd -14 (C=0.8l3, CHCl 1 max. (in ethanol) 2700,

"EXAMPLE '10 Preparation ,of 3-acetoxy-7,11-diketotigogenin from 3- acetoxy-7,I I -diketo-8-dehydro tigo gen in A mixture of mg: of 3-acetoxy-7,l1-diketo-8-dehydrotigogen in 4 ml. glacial acetic acid, one drop of water, and 400' mg.-of zinc dust was heated on the steam bath for one hour. The-mixture was cooled, and 30 ml. of water and 20 ml. of chloroform were added. After shaking thoroughly andfiltering, the layers were separated, and the aqueous layer was extracted twice with five ml. portions of chloroform. The combined chloroform extracts'were dried over sodium sulfate, and concentrated in vacuo. Recrystallization of the residue gave small rectangular prisms. Yield: 75 mg., M. P. 24l-243 C., [(11 -72 (C=.0.827,CHC1

EXAMPLE 11 Preparation of A t-allapregnene-3-ol-7,11,20-tri0ne-3-acetate from A-allopregnene-3,7,11-tri0l-20-0ne-3-acetate Seven hundred and eighty milligrams of A -allopregnene-3,7,l1-triol-20-one-3-acetate in 20 ml. of acetone were oxidized'with 2.66 rnillimols of chromium trioxide in Z ml. of 10% aqueous sulfuric acid. After isolating the product in'the usual-way, it was recrystallized from methanol to give 260 mg. of pale yellow prisms., M. P. 177-l79 -C., [111 5 +71- (C=l.l2, CHCl A max. 2690,

EXAMPLE 12 Preparation of allopregnan-3-ol-7,l1,20-trione-3-acetate from .N-allopregnene-S-ol-ZI 1 ,20-tri0ne-3-acetate A mixture of 210 mg of A" -allopregnene-3-ol-7,11,20- trione-3-acetate, 10 ml. of glacial acetic acid, two drops of water, and 1.0 g. of zinc dust was heated on the steam bath for 1 hour. The product was isolated in the usual manner, and recrystallized from methanol to give mg. of hexagonal prisms, M. P. 214-215 C.

Various changes and modifications may be made in carrying out the present invention without departing from the spirit and scope thereof. Insofar as these changes and modifications are within the purview of the annexed claims, they are to-be considered as part of our invention.

We claim:

I. A 3-acyloxy-7;11-diketo-S-dehydrotigogenin wherein the acyl substituent is a lower fatty acid radical.

2. 3-acetoxy-7,11-diketo-8-dehydrotigogenin.

No references cited. 

1. A 3-ACYLOXY-7,11-DIKETO-8-DEHYDROTIGOGENIN WHEREIN THE ACYL SUBSTITUENT IS A LOWER FATTY ACID RADICAL. 